We used two different version cyclonepro image creation utility(V863 and V856)on the same chip, and get the different trim value, even Prog HC08 flash programmer gets the different trim value, MC908QB8 is old part, should have no update algorithm, right? pls help how to get the right trim value, now we have some issue in communication after programming, but it is mass production for long time, only recently has this issue.Thanks a lot!

Are you testing on one chip, or you are getting different trim values for different chips?

Trim is not necessarily going to be the same for every chip. It is a calibration based on calculations that the P&E hardware and firmware generate. However, if you are using the same chip and the values are different between image creation and firmware versions, then that is a problem.

Dear Takao: Yes! Do test on the same chip, this is why we need your help. Becuase this impact SCI communication, we failed to communicate by SCI, after checking, we find that we can different trim value in image creation, even different version of image creation, and get the different trim value. Thanks!